Mulligans
This fight is exactly like that one Tavern Brawl, so look to outvalue your opponent with specific minions like Cairne, Cenarius, and Druid of the Fang (you might have thought a 4 mana 7/7 was OP, try a 1 mana 7/7). You could swap shredders or savage combatant for spell damage, but savage combatant helps with trading against his early game minions.